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4675 |
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Thursday, May 12, 2016, Room 3G 2:40 PM Plasma Spraying |
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Microstructure and mechanical property of Al2O3/YAG wear-resistant composite coating deposited by atmospheric plasma spraying |
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Kai Yang* / Shanghai Institute of Ceramics, Chinese Academy of Sciences, P.R. China Jian Rong / Shanghai Institute of Ceramics, Chinese Academy of Sciences, China Chengguang Liu/ Shanghai Institute of Ceramics, Chinese Academy of Sciences, China Shunyan Tao/ Shanghai Institute of Ceramics, Chinese Academy of Sciences, China Chuanxian Ding/ Shanghai Institute of Ceramics, Chinese Academy of Sciences, China |
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Plasma sprayed Al2O3 ceramic coatings show great engineering potential in the combined working conditions such as high specific pressure, high temperature, serious oxidation and thermal shock. Strengthening and toughening from grain refinement or solid solution may be beneficial to the improvement of the strength and toughness of the Al2O3 coating. However, poor high-temperature microstructure stability restricts some practical applications. Therefore, an interesting work has been taken in this article. The spray-dried Al2O3/Y2O3 composite powder was prepared using commercially available nano-sized Al2O3 and Y2O3 feedstock. The Al2O3/Y3Al5O12(YAG) eutectic structure in the coating is expected to be obtained due to high enthalpy, large temperature gradient and rapid solidification in plasma spraying process. Interestingly, the as-sprayed coating showed obvious amorphous feature, which may be conducive to the anti-corrosion performance. After heat treating, the coating is composed of the crystalline phases of ±-Al2O3 and YAG. The phase composition, microstructure, mechanical and thermal properties of Al2O3/YAG composite coating were investigated. The tribological performance of the coating was also evaluated. Owing to larger structure stability, lower porosity, greater thermal conductivity and stronger interface bonding, the Al2O3/YAG composite coating shows better wear-resistant property than the pure Al2O3 coating under the severe conditions. Keywords: Al2O3/YAG composite coating; Plasma spraying; Microstructure; Mechanical and thermal properties; Tribological performance |